Downdetector.com indicated the outage started at about 4:30 p.m. and lasted for about four hours.

Tesla confirmed the mobile app was "briefly unavailable" Monday and was restored "soon after." Several users said it was 3-4 hours.

Tesla said it provides owners with a few options to locking, unlocking and starting their vehicles, including a physical key fob or key card, which the company has long encouraged owners to carry in case their phone dies, as well as the ability to use the Tesla mobile app. And Model 3 owners can use their phones as a key, the company said.

The Model 3’s phone-as-key function uses Bluetooth Low Energy to communicate with the vehicle, and thus full app functionality is not required to lock, unlock and start the car, Tesla said.

The phone-as-key functions separately from the in-app lock-unlock features, which require a cell signal and are not a primary means of entrance, exit and vehicle usage, the company said.

As a result, Tesla said there was no impact to phone-as-key functionality as long as users remained logged into their accounts.

@Tesla what’s the status of the network? I’m stuck at a supercharger, plugged in. Trying to get home with a dead key fob, was using the app to run the car. Now the system’s down for 3 hours. Help!